Adrenergic Drugs Flashcards

(99 cards)

1
Q

How does the composition interstitial fluid compare to sea water?

A

Very similiar

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2
Q

How does the concentrations of solutes in the cytoplasm of a human cell compare to interstitial fluid and sea water?

A

Na much lower
K much higher
Ca exponentially lower
Cl lower (been replaced by proteins)

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3
Q

What is a minor component of the resting potential of a cell?

A

Ion flux from the NaK ATP-ase pump

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4
Q

What is a major component of the resting potential of a cell?

A

The different membrane permeabilities of Na and K

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5
Q

Is there more Na or K permeability in a cell?

A

K is 100x more permeable than Na

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6
Q

How long does the the efflux of K continue?

A

The net efflux of K+ out of the cell (due to the concentration gradient) continues until the electrical force leading K+ outside is balanced by the electrical force of Cl- bringing it back

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7
Q

What is the significance of membrane potential?

A

Changes in membrane potential in nerve and muscles above a threshold lead to an AP

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8
Q

What would happen in a cell, if it suddenly became permeable to Na in a location?

A

At that site, the Na channel would counteract the K current, leading to depolarization

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9
Q

Voltage gated channels

A

Special membrane proteins on excitable cells

Open or close based on the potential differences across the membrane

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10
Q

Do K or Na voltage gated channels respond quicker?

A

Na voltage gated channels respond quicker

K voltage gated channels respond slower

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11
Q

How do the rates of AP compare in cardiac tissue, nerves, or skeletal muscle?

A

Cardiac AP are much slower to prevent tetanic contraction

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12
Q

What are the steps of synaptic transmission?

A

1) AP reaches the terminal and Ca channels open
2) Ca entry leads to transmitter release
3) Receptors open Na channels and AP occurs on post-synaptic cell

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13
Q

What makes up the central nervous system?

A

Brain and Spinal cord

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14
Q

What makes up the peripheral nervous system?

A

Nerves and ganglia outside the brain and spinal cord

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15
Q

What are the divisions of the peripheral nervous system?

A

Efferent

Afferent

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16
Q

What are the divisions of the efferent nervous system?

A

Somatic nervous system

Autonomic nervous system

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17
Q

Somatic nervous system

A

Motor innervation of all skeletal muscles

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18
Q

Autonomic nervous system

A

Sympathetic and parasympathetic divisions

Motor innervation of smooth muscle, cardiac muscle, and glands

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19
Q

Efferent nervous system

A

Projects from the CNS to targets and elicits appropriate responses from the target

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20
Q

Afferent nervous system

A

Projects from the target to the CNS to provide information

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21
Q

What are the divisions of the afferent nervous system?

A

Somatic sensory

visceral sensory

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22
Q

Somatic sensory system

A

Senses the external environment

Made up of general and special divisions

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23
Q

Visceral sensory system

A

Senses the internal environment

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24
Q

What is homeostasis?

A

Ability of a higher animal to maintain internal stability

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25
What divisions of the nervous system are responsible for maintaining homeostasis?
The autonomic nervous system and endocrine system
26
What are the differences in the regions of origin of the sympathetic and parasympathetic ns?
``` Sympathetic = thoracolumbar region Parasympathetic = Craniosacral region ```
27
What are the differences in the locations of ganglia of the sympathetic and parasympathetic systems?
``` Sympathetic = close to the spinal cord Parasympathetic = close to the target organs ```
28
What are the differences in the length of postganglionic fibers of the sympathetic and parasympathetic fibers?
``` Sympathetic = long Parasympathetic = short ```
29
What are the differences in the postganglionic branching of the sympathetic and parasympathetic fibers?
``` Sympathetic = lots, so multiple organs can be mobilized at once Parasympathetic = very little branching ```
30
What are the primary neurotransmitters of the sympathetic system? What do they target?
Epinephrine (via blood) Norepinephrine (post-ganglionic neuron) They target adrenergic receptors
31
What is the primary neurotransmitter of the parasympathetic system? What receptors do they target?
Acetylcholine | Targets muscarinic receptors
32
What is the primary neurotransmitter of the somatic system? What receptor is targeted?
Acetylcholine | Targets nicotinic receptors
33
T/F - Most organs have both sympathetic and parasympathetic innervation?
True - So multiple transmitters and classes of drugs that affect the functioning of the organ This will influence the effect of a given autonomic drug on a given target organ
34
What happens to adrenergic transmitters in the synapse?
Transmitter is transported back in the postsynaptic terminus? Drugs can prevent them from being brought back in
35
What happens to cholinergic transmitters in the synapse?
Neurotransmitter is hydrolyzed in the synapse
36
T/F - AP continues once it reaches the target organ?
False - Once the AP reaches the target, it's going to make the organ do something
37
What are the major types of adrenergic amines?
Dopamine Norepinephrine Epinephrine
38
Where are dopamine receptors located?
CNS Kidney Smooth muscles in the periphery
39
What are the major types of adrenergic receptors?
a1, a2, B
40
What are the a1 receptor subtypes?
a1(A, B, D)
41
What are the a2 receptor subtypes?
a2(A, B, C)
42
What are the B receptor subtypes?
B1, B2, B3
43
What are the most important adrenergic receptors in the PNS?
a1, B1, B2
44
Where are adrenergic receptors located?
CNS | Target organs of the sympathetic ns
45
Where are a1 receptors located?
Smooth muscle cells
46
What do a1 receptors do when stimulated?
Increase Ca This increases the activity of MLCK, which increases MLC phosphorylation This all ultimately increases smooth muscle contractility
47
What do a2 receptors do?
They are most important on presynaptic termini Inhibit epinephrine and norepinephrine release in the CNS and PNS -they sense how much epi and norepi are around, if there's too much, they prevent them from being released
48
What will an a2 agonist do?
Attenuate CNS response Vasodilate Decrease HR
49
What will an a2 antagonist do?
Enhance CNS response Vasoconstrict Increase HR
50
What will an a1 agonist do?
Vasoconstrict | Produce contraction of vascular smooth muscle
51
What will an a1 antagonist do?
Vasodilate
52
Where are B2 receptors located?
Smooth muscle cells
53
What will B2 receptors do when stimulated?
This will activate K channels, leading to hyperpolarization, a reduction of Ca, and muscle relaxation due to the activity of MLCK
54
Where are B1 receptors located?
Cardiac muscle cells
55
What will B1 receptors do when stimulated?
Activate PKA and L-type Ca channels - increasing Ca levels and muscle contractility
56
What will a B1 agonist do?
Improve contractility of the failing heart | Increase HR
57
What can excess of a B1 agonist cause?
Arrhythmias
58
What will a B2 agonist do?
Lead to vascular and non-vascular smooth muscle relaxation | Reduce BP, bronchodilation, reduce uterine contraction
59
What receptors does epinephrine activate?
a, B1, B2
60
What receptors does norepinephrine activate?
a and B1 | does not activate B2
61
What does systemic effects of endogenous agonists depend on?
Administration and dose | A decrease in concentration leads to a decrease in receptor stimulation
62
What are the cardiac effects of epinephrine and norepinephrine?
Mainly B1 effects
63
What are the smooth muscle effects of epinephrine and norepinephrine?
Usually relaxation mediated by B2 receptors GI decreased motility Bronchodilation However, a receptors mediate sphincter contraction
64
What are the effects on salivary glands of epinephrine and norepinephrine?
Modest secretion with a high concentration of protein | Mainly a1 and B1, but some B2 - protein secretion comes from B1
65
What are the effects of epinephrine and norepinephrine on the CNS, when administered peripherally?
Nothing - does not cross the blood-brain barrier
66
What is anaphylaxis?
Severe whole body response to an allergen | Includes smooth muscle constriction, vasodilation (severe hypotension), and increased vascular permeability
67
Why is epinephrine used to treat anaphylaxis?
Standard emergency treatment Stimulates a receptors (increase BP) Stimulates B1 receptors (positive cardiac effects) Stimulates B2 receptors (bronchodilation)
68
What are major examples of a1 agonist drugs?
Levonordefrin | Metarminol
69
Levonordefrin
Sometimes used in conjunction with local anesthesia
70
Metarminol
Used to treat hypotension during surgery
71
Why is epinephrine or levonordefin used in conjunction with local anesthetics?
1) Prolong the duration of the nerve block, and improve the likelihood of its success 2) Diminish systemic toxicity of anesthesia 3) Minimize blood loss during surgical procedures (these are all due to their hypertensive effects)
72
What can a2 agonist drugs be used for?
Treat hypertension via autonomic regulation of the cardio system Muscle relaxants ADHD treatment Sedative
73
What conditions can B1 agonist drugs be used for?
Primarily heart failure and cardiogenic shock via direct stimulation of B1 receptors
74
What conditions can B2 receptor agonists be used for
``` Respiratory diseases (mainly) can also be used to produce vasodilation in muscle and liver, and relaxation of uterine tissue ```
75
What can dose related complications come from?
- Too large a dose - accidental IV injection - heightened sensitivity - patient cardiovascular disease
76
What can a1 antagonists be used to treat?
Therapies relating to antagonism of vascular smooth muscle constriction - hypertension - pulmonary hypertension - hemodynamic shock - Rynaud's disease Antagonism of bladder smooth muscle contraction -Benign prostatic hyperplasia
77
What are the major examples of a1 antagonists?
``` Prazosin Terazosin Doxazosin Alfuzosin Tamulosin ```
78
Why might Prazosin be more beneficial? Why might Terazosin or Doxazosin be more beneficial?
Prazosin is the first a-selective antagonist Terazosin and Doxazosin have longer half lives and only need to be taken once a day All are used to treat hypertension
79
Alfuzosin
Acts primarily on the smooth muscle of prostate (BPH drug) | Likely to reflect the selective accumulation in prostate tissue
80
Tamulosin
Specific for a1A and a1D receptors and selective for prostate Effective to treat BPH Does not increase BP (a1 antagonist)
81
What do non-selective a-adrenergic receptor antagonist do?
Block the transmitter mediated feedback loop
82
What do agonists of B3 do?
Produce vasodilation
83
What do antagonists of B3 do?
No clinical use
84
Why are B-blockers either non-selective (B1 and B2) or B1 specific?
Blockage of B2 would be undesirable in airway smooth muscle, vascular smooth muscle, and endocrine cells
85
What is the cardiac effect of B-blockers?
Decrease HR and force of contraction of the heart
86
What is the blood pressure effect of B-blockers?
Diminish renin release form the kidney. Renin is important in BP regulation, and therefore the diminish of renin drops BP Cardiac effects may indirectly contribute to this drop as well
87
Intrinsic Sympathomimetic Activity (ISA)
Some B-blockers have a slight ISA, and the consequence is low B stimulation They have a high affinity for B-receptors, but no or low capacity to activate the receptors
88
B-blockers without ISA
Decrease resting HR, plasma renin activity, and cardiac output
89
B-blockers + ISA
Do not depress cardiac function or plasma renin activity as well as without ISA But they do attenuate against increases
90
What can B-blockers be used to treat?
``` Hypertension Ischemia Heart disease Post-MI Congestive heart failure Arryhthmias Glaucoma (In CNS) - Migraines and tremors associated with anxiety ```
91
T/F - some drugs are both a and B antagonists
True | Labetalol and Carvedilol
92
Labetalol
7x as potent as normal B-blocker ISA activity Used in long term management of hypertension
93
Carvedilol
No ISA affect Effective treatment of congestive heart failure Antioxidant activity
94
What are adverse effects of B-blockers on the heart?
Bradycardia AV block Withdrawal can lead to angina, myocardial infarction, or death
95
What are adverse effects of B-blockers on smooth muscle?
Non-selective blockers can reduce vasodilation responses | Increased bronchospasms
96
What are adverse effects of B-blockers on the CNS?
``` Depression Fatigue Sleep disturbance Hallucination Dizziness ```
97
What dental adverse effect can a-blockers have?
Orthostatic hypotension | -special care should be taken to prevent an accident
98
What should dentists be aware of with a patient taking B-blockers?
More at risk for hypertensive episode after receiving with vasoconstrictor
99
What adverse dental effect does Clonidine have?
Causes Xerostomia